An alternate system uses a fog or fine mist injected in to the intake air stream. Although many commercial systems are available, growers can assemble and install their own system using a high pressure piston pump and fog nozzles. The essential components are proven in Fig. 1. A two-stage system controlled by a two- stage thermostat enables more water to be applied on excessively warm, shiny days. Temperature settings should be 5-10°F apart.
Algae growth in the pads may become a problem that will reduce the effectiveness of the machine and result in accelerated deterioration of the pads. The addition of an algaecide to the drinking water supply will help in control.
It really is desirable, especially in hard drinking water areas, to include a wetting agent to the water to obtain additional uniform wetting of the pads. A commercial material or liquid home detergent at the rate of 2 tablespoons per 100 gallons can be used.
Water for the pads should be clean and lower in mineral content to Greenhouse Auto Vent prevent clogging and coating of the pads. A 
pump, pipes and gutters are accustomed to recirculate the water. A flow rate 113 gallon each and every minute per linear foot of pad program ought to be provided to make certain adequate wetting.
In the most typical cooling system (fan and pad), the fans draw air through wet pads that expand the length of 1 endwall or sidewall. Aspen and coated cellulose are normal pad materials that usually have life of one to 3 years. Approximately one sq . foot of pad are is necessary for 20 square feet of floor area.